RealmCollection

The Realm which manages the collection, or nil for unmanaged collections.

Indicates if the collection can no longer be accessed.

The collection can no longer be accessed if invalidate() is called on the Realm that manages the collection.

The number of objects in the collection.

A human-readable description of the objects contained in the collection.

Returns the index of an object in the collection, or nil if the object is not present.

Returns the index of the first object matching the predicate, or nil if no objects match.

Returns the index of the first object matching the predicate, or nil if no objects match.

Returns a Results containing all objects matching the given predicate in the collection.

Returns a Results containing all objects matching the given predicate in the collection.

Returns a Results containing the objects in the collection, but sorted.

Objects are sorted based on the values of the given key path. For example, to sort a collection of Students from youngest to oldest based on their age property, you might call students.sorted(byKeyPath: "age", ascending: true).

Returns a Results containing the objects in the collection, but sorted.

Returns the minimum (lowest) value of the given property among all the objects in the collection, or nil if the collection is empty.

Returns the maximum (highest) value of the given property among all the objects in the collection, or nil if the collection is empty.

Returns the sum of the given property for objects in the collection, or nil if the collection is empty.

Returns the average value of a given property over all the objects in the collection, or nil if the collection is empty.

Returns an Array containing the results of invoking valueForKey(_:) with key on each of the collection’s objects.

Returns an Array containing the results of invoking valueForKeyPath(_:) with keyPath on each of the collection’s objects.

Invokes setValue(_:forKey:) on each of the collection’s objects using the specified value and key.

Registers a block to be called each time the collection changes.

The block will be asynchronously called with the initial results, and then called again after each write transaction which changes either any of the objects in the collection, or which objects are in the collection.

The change parameter that is passed to the block reports, in the form of indices within the collection, which of the objects were added, removed, or modified during each write transaction. See the RealmCollectionChange documentation for more information on the change information supplied and an example of how to use it to update a UITableView.

At the time when the block is called, the collection will be fully evaluated and up-to-date, and as long as you do not perform a write transaction on the same thread or explicitly call realm.refresh(), accessing it will never perform blocking work.

Notifications are delivered via the standard run loop, and so can’t be delivered while the run loop is blocked by other activity. When notifications can’t be delivered instantly, multiple notifications may be coalesced into a single notification. This can include the notification with the initial collection.

For example, the following code performs a write transaction immediately after adding the notification block, so there is no opportunity for the initial notification to be delivered first. As a result, the initial notification will reflect the state of the Realm after the write transaction.

let results = realm.objects(Dog.self)
print("dogs.count: \(dogs?.count)") // => 0
let token = dogs.observe { changes in
switch changes {
    case .initial(let dogs):
        // Will print "dogs.count: 1"
        print("dogs.count: \(dogs.count)")
        break
    case .update:
        // Will not be hit in this example
        break
    case .error:
        break
    }
}
try! realm.write {
    let dog = Dog()
    dog.name = "Rex"
    person.dogs.append(dog)
}
// end of run loop execution context

You must retain the returned token for as long as you want updates to be sent to the block. To stop receiving updates, call invalidate() on the token.

Returns the minimum (lowest) value of the collection, or nil if the collection is empty.

Returns the maximum (highest) value of the collection, or nil if the collection is empty.

Returns the minimum (lowest) value of the collection, or nil if the collection is empty.

Returns the maximum (highest) value of the collection, or nil if the collection is empty.

Returns the sum of the values in the collection, or nil if the collection is empty.

Returns the average of all of the values in the collection.

Returns the sum of the values in the collection, or nil if the collection is empty.

Returns the average of all of the values in the collection.

Returns a Results containing the objects in the collection, but sorted.

Objects are sorted based on their values. For example, to sort a collection of Dates from neweset to oldest based, you might call dates.sorted(ascending: true).

Returns a Results containing the objects in the collection, but sorted.

Objects are sorted based on their values. For example, to sort a collection of Dates from neweset to oldest based, you might call dates.sorted(ascending: true).